• Journal of the Korean Chemical Society
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• v.28 no.1
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• pp.54-61
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• 1984

The species and equilibrium of molybdate and tungstate have been investigated from the elution behaviors of those in various concentrations of nitric acid and the UV spectra obtained at the various Z values. In higher concentrations than 0.05M nitric acid, the nitarte complex species of $MoO_2(NO_3)_2$ seems to form from the $MoO_2^{2+}$ ions formed by the following equation: $Mo_8O_{26}^{4-} + 20H^+$ ${\rightleftharpoons}$ $8MoO_2^{2+}$ + $10H_2O$. In the case of tungstate, the elution behaviors of tungstate in nitric acid medium are similar to those of perchloric acid, so we think the equilibrium of tungstate existed in perchloric acid could be also existed in nitric acid. These elution behaviors of tungstate are compared with the UV spectra obtained at the various Z values.

• Korean Journal of Food Science and Technology
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• v.36 no.3
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• pp.518-521
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• 2004

Ginseng saponin was isolated from panax ginseng root using high-speed countercurrent chromatography (HSCCC). Preliminary studies were performed to optimize physical properties of two-phase solvent system and operating parameters including rotation speed of column, elution mode of mobile phase, and flow rate. Two-phase solvent system for isolation of ginseng saponins was composed of chloroform, water, and methanol as blending solvent. Chloroform-aqueous methanol (4:6) systems with various concentration of methanol in water were evaluated for retention of stationary phase in column. Retention of stationary phase decreased with increasing flow rate in tail-to-head elution mode using upper phase as mobile phase and head-to-tail elution mode using lower phase as mobile phase. Latter mode produced high retention at flow rate of 5 mL/min. Optimum conditions for isolation of saponin were chloroform/methanol/water (40/39/21) solvent system; mobile phase, of lower organic layer, flow rate, of 5 mL/min, head to tail elution mode, rotation speed, of 800 rpm, and sample injection, of $200{\mu}L$, Recovery yield of ginseng saponin from panax ginseng root extract by HSCCC was 63.6%, and the purity of HSCCC fractions was verified by TLC.

• Korean Journal of Food Science and Technology
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• v.25 no.6
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• pp.698-702
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• 1993

Effect of heating temperature on elution patterns of soluble carbohydrate of legume starches and the texture of starch gels was investigated. The elution profiles of soluble carbohydrate obtained by Sepharose 2B-CL showed that the larger molecules were leached as the heating temperature increased. The elution profiles of soluble carbohydrate of cow pea and mung bean starches were similar, but those of kidney bean starch were different. The gel structures of cow pea and mung bean were stable with showing high values in hardness and cohesiveness. But red bean and kidney bean gels were weak in hardness and cohesiveness. As the heating temperature rised, hardness and cohesiveness were increased in gels prepared by heating for 15 min. However, the gels made by heating for 1 hour showed that less hard and more cohesive gels from cow pea and mung bean, while harder and more cohesive gels from red bean and kidney bean were obtained as the heating temperature increased from $85^{\circ}C\;to\;95^{\circ}C$.

• Journal of Technologic Dentistry
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• v.31 no.3
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• pp.21-26
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• 2009

Purpose: Standards of alloy for porcelain fused to metal crown be classified by metallic factor and biological factor. Metallic factors consist of stability of alloy composition and mechanical strength and surface characteristics for chemical bond. Biological factors be considered properties of metallic elements and problems originated by toxicity and hypersensitive reaction. Alloys considered such controversial points are the most suitable alloy for dental instrument. Method: Alloys added Be and Nb using Ni-Cr alloy which has been widely used for dental instrument be selected and classified experimental group. Non-addition Be and Nb to Ni-Cr alloy classify control group and addition Be alloy is Be-experimental group, addition Nb alloy is Nb-experimental group. Specimens for cytotoxicity analysis gave effect to washing and sterilization. and then made an experiment on elution with cell medium after disinfection. It conducted specimens within cell medium with 24hours, 48hours, 72hours, respectively. It cultured human dermal fibroblast(HDF) using cell medium for cytotoxicity test and then investigated elution rate through spectroscopic analysis by MTT-assay. Result: As results of cytotoxicity test by MTT-assay, cultured cell rate of VII measured more low numerical value within elution medium for 24hours focused on control group. Also, cultured cell rate of K3 alloys observed low value for 48hours, 72hours than value of control group. Conclusion: According to final result that synthesize above results, Ni-Cr alloy added Be and Ni has little difference in Cytotoxicity by MTT-assay.

• Journal of the Korean Applied Science and Technology
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• v.31 no.2
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• pp.305-312
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• 2014

The following study is the result of herbal teas puffed at different temperatures between $140{\sim}220^{\circ}C$. There was change of single breadth that some carbonization occurs according to rise of processing temperature and crude ash content rises relatively, and crude protein and crude fat content had hardly changed and moisture content decreased. The solid elution rate of the herbal teas appeared by 0.18~0.27% (w/w), it increased as puffing temperature rises. The reason for the increase in solid elution rates is due to the breakage of cross bridges between the raw materials in the herbal tea which are carbohydrates, proteins, lipids and etc. after treatments of physical changes rather than chemical ones. Benzopyrene content happened difference in B(${\alpha}$)P content according to processing temperature, raw material by 0.18~0.24 ppbs.

• Korean Journal of Food Science and Technology
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• v.34 no.2
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• pp.343-345
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• 2002

The study was investigated hot-water soluble on waxy black and waxy rice flours according to gelatinization temperatures and heating time. The hot-water soluble contents of both samples were increased during heating time at $90^{\circ}C$. The waxy black and waxy rice flours solutions according to gelatinization temperatures ($80^{\circ}C,\;90^{\circ}C,\;95^{\circ}C\;and\;98^{\circ}C$) were heated for 10, 20 and 30 min. Determination of elution patterns of rice flours was used by Sepharose CL-2B column. As a result, the elution patterns were eluted the most in void volume ($V_0$) and the elution patterns of the hot-water solubles were increased according to heating time and gelatinization temperatures.

• Korean Journal of Food Science and Technology
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• v.29 no.5
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• pp.1067-1070
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• 1997

Imunoglobulins from bovine plasma proteins were isolated by IMAC which $Cu^{2+}$ was chelated on a chelating sepharose fast flow gel. Most plasma proteins were eluted by 1st (0.01 M $Na_2HPO_4$, 0.5 M NaCl, pH 4.0) and 2nd elution buffers (0.01 M imidazol). According to the reverse phase HPLC analysis, it was found that proteins which were eluted by 1st elution buffer were mainly composed of serum albumin, while most IgG and transferrin were eluted by 2nd elution buffer. When protein fractions obtained by 2nd elution buffer was applied to ultra filtration system (molecular weight cut off: 100 kD), IgG was further purified. These results indicate that IMAC is an excellent tool for isolating imunoglobulins from plasma proteins.

• Journal of Korean Society of Environmental Engineers
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• v.31 no.7
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• pp.557-564
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• 2009

The objective of this study is to efficiently recover phosphorus contained in sewage sludge by a struvite-forming method. The performances were evaluated under various operating conditions(elution with the kind of acid, Mg-compound and temperature) in order to reach the optimum conditions of struvite-forming. As a result, as an elution solution, the elution efficiency of $H_2SO_4$ was 2.65 times higher than that of HCl. Also, the precipitation efficiency of struvite was the highest (97.4%) in case of using $MgCl_2{\cdot}6H_2O$ as Mg-compounds at $25^{\circ}C$. However, the side reaction by Fe, Al and Zn appeared in process of phosphorus recovery. To solve some problems caused by side reacton, large quantities of co-precipitation materials produced by side reaction were removed by precipitating phosphorus compounds in pH 7. Consequently, the recovery efficiency of phosphorus by a struviteforming method was 82.99%, and purity of the recovered struvite product was high.

• Journal of Radiation Industry
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• v.11 no.1
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• pp.47-54
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• 2017

Compared to other occupations, there is a greater risk of exposure to radiation due to the use of radioisotopes in nuclear medicine for diagnostic evaluations and therapy. To consider ways to reduce exposure dose for those in nuclear medicine involved in injection work and elution work among radiation workers as well as for sanitation workers and trainees among frequent workers an investigation into exposure dose and situational analysis from changes in yearly exposure dose evaluations, changes in work environment and changes in forms of inspection were conducted. Exposure dose measurements were taken by using EPD MK2 worn during working hours for one injection worker, one elution worker, two sanitation workers, and one trainee at a general hospital in the Seoul area for three days from July 18th to 20th 2016. Radiation from radioisotopes which are a part of nuclear medicine can significantly affect not only radiation workers who deal with radioisotopes directly but also frequency works as well. According to this study the annual dose limit for elution workers and injection workers were considered safe as the amount of exposure was not large enough to have a significant effect. The limits of this study consist in the duration of this study and the quantity of participants. Also there was a limitation of the measurement device involving accumulated exposure, where the EPD MK2 cannot check the changes in exposure according to a particular activity.

• Biomaterials and Biomechanics in Bioengineering
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• v.2 no.3
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• pp.159-172
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• 2015

Treatment of polymicrobial infected musculoskeletal defects continues to be a challenge in orthopaedics. This research investigated single and dual-delivery of two antibiotics, vancomycin and amikacin, targeting different classes of microorganism from a biodegradable calcium sulfate-chitosan-nHA microsphere composite scaffold. The addition of chitosan-nHA was included to provide additional structure for cellular attachment and as a secondary drug-loading device. All scaffolds exhibited an initial burst of antibiotics, but groups containing chitosan reduced the burst for amikacin at 1hr by 50%, and vancomycin by 14-25% over the first 2 days. Extended elution was present in groups containing chitosan; amikacin was above MIC ($2-4{\mu}g/mL$, Pseudomonas aeruginosa) for 7-42 days and vancomycin was above MIC ($0.5-1{\mu}g/mL$ Staphylococcus aureus) for 42 days. The antibiotic activity of the eluates was tested against S. aureus and P. aeruginosa. The elution from the dual-loaded scaffold was most effective against S. aureus (bacteriostatic 34 days and bactericidal 27 days), compared to vancomycin-loaded scaffolds (bacteriostatic and bactericidal 14 days). The dual- and amikacin-loaded scaffolds were effective against P. aeruginosa, but eluates exhibited very short antibacterial properties; only 24 hours bacteriostatic and 1-5 hours bactericidal activity. For all groups, vancomycin recovery was near 100% whereas the amikacin recovery was 41%. In conclusion, in the presence of chitosan-nHA microspheres, the dual-antibiotic loaded scaffold was able to sustain an extended vancomycin elution longer than individually loaded scaffolds. The composite scaffold shows promise as a dual-drug delivery system for infected orthopaedic wounds and overcomes some deficits of other dual-delivery systems by extending the antibiotic release.